Lettuce harvesting apparatus and method therefor

ABSTRACT

A mobile harvesting apparatus and method, which permits the automated harvesting of produce, preferably lettuce. The apparatus consists in its most basic form of a vehicle having a bandsaw positioned at a front portion thereof, the blade of which is positioned to slice the lettuce head at the desired location. The apparatus further includes a conveyor, that transports the harvested produce from the cutting site and onto the apparatus. Preferably, the apparatus additionally features a washing conveyor, washing station, inspection station, and elevator conveyor, to assist in the further processing of harvested produce.

RELATED APPLICATION

[0001] This non-provisional application claims priority from provisionalapplication No. 60/368,990, filed on Apr. 2, 2002.

FIELD OF INVENTION

[0002] This invention relates generally to apparatuses and methods forharvesting produce and, more specifically, to a mobile lettuce harvesteradapted to permit the automated harvesting of lettuce heads.

BACKGROUND OF THE INVENTION

[0003] Generally, the harvesting of produce, including in particularlettuce, involves the manual removal of produce from the field.Typically, a farmworker will walk through a field with a cutting toolsuch as a knife, and manually detach the exposed lettuce head from itsroot. The lettuce head will then be delivered for further processing,perhaps to a conveyor belt on a self-propelled harvester travellingthrough the field alongside the worker.

[0004] There are several drawbacks with the prior art methods, however.They are labor-intensive and, because of the use of a sharp cuttingimplement by the workers, potentially dangerous. A need thereforeexisted to reduce the labor-intensity of the produce harvesting process,and also to make that process safer. Preferably, account should also betaken of other steps necessary in the harvesting process beyond theremoval of the produce from the ground, including inspection, washing,and elevation of the produce to a container. The present inventionsatisfies this need and provides other, related advantages.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide a mobileharvester permitting automated harvesting of produce, includingspecifically lettuce.

[0006] It is a further object of the present invention to provide amobile harvester permitting automated harvesting of produce, and furtherhaving a conveyor belt, a washing station, and an elevator belt.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In accordance with one embodiment of the present invention, aself-propelled harvester is disclosed. The harvester comprises, in

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a side view of an embodiment of the lettuce harvestingapparatus of the present invention.

[0009]FIG. 2 is a front view of the lettuce harvesting apparatus of FIG.1.

[0010]FIG. 3 is a side view of another embodiment of the lettuceharvesting apparatus of the present invention.

[0011]FIG. 4 is a front view of the lettuce harvesting apparatus of thepresent invention, illustrating in greater detail the bandsaw portion ofthe apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Referring first to FIG. 1, an embodiment of the lettuceharvesting apparatus 10 (“apparatus 10”) of the present invention isshown. The apparatus 10 is intended to be used for the harvesting ofproduce. It is preferred to use the apparatus 10 to harvest lettuce, andin particular romaine lettuce.

[0013] The major components of the apparatus 10 include a bandsaw 12, afeed conveyor 14, a lift conveyor 16, a washing conveyor 18, a washingstation 20, a transfer conveyor 22, and an elevator conveyor 24. Theapparatus 10 is powered by an engine 26, rides on wheels 28, and may bedriven by a person 29 sitting in driving compartment 30.

[0014] The bandsaw 12 is positioned at the front of the apparatus 10 asshown in FIGS. 1-4. The exposed cutting blade 15 of the bandsaw 12 ispositioned at the base of the feed conveyor 14. The height of thebandsaw 12 and thus of the exposed cutting blade 15 is preferablyadjustable, and the desired height setting will depend on the specificproduce to be cut. Generally, with romaine, the height of the exposedcutting blade 15 will be set between 0.25″ and 1.5″ from the ground. Thelevel of the bandsaw 12, and thus of the exposed cutting blade 15, ispreferably also adjustable, as herein described.

[0015] Preferably, the bandsaw 12 further comprises a housing 17, whichconceals the cutting blade 15 after it passes across the area where itwill be cutting the produce, and continues to loop upward and around.(The path of the cutting blade 15 is illustrated in FIG. 4.) The purposeof the housing 17 is to increase safety for persons who might be workingwith the apparatus 10. The bandsaw 12 is preferably poweredhydraulically, though of course other powering means may be employed.

[0016] The feed conveyor 14 is coupled to the lift conveyor 16 withcoupling arms 32, which coupling arms 32 are to travel in an upward anddownward direction about point B, i.e., about the point at which theycouple to the lift conveyor 16. The feed conveyor 14 preferably rides onfive parallel rollers 34 (only one is shown), with the rollers 34 beingpositioned about axle 35 and with axle 35 being coupled at each endthereof to a substantially L-shaped member 37. Each substantiallyL-shaped member 37 rotates about point B, and is coupled at its secondend (the first end being coupled to axle 35) to a hydraulic cylinder 13(only one of which is shown). (It should be understood that fewer thanfive, or more than five, rollers 34 could be provided, and further thatthey could be positioned in a non-parallel configuration.) It is furtherpreferred to position scrapers (not shown) above each roller 34,oriented so as to remove dirt or debris that adheres to the surface ofthe rollers 34 as the apparatus 10 travels through a field to beharvested.

[0017] The feed conveyor 14 is coupled to the coupling arms 32 withfirst vertical supports 36 and second vertical supports 38. The firstvertical supports 36 include a spring and shock assembly 40 thereon, soas to permit upward and downward movement of the front portion of thefeed conveyor 14, as indicated by the bi-directional arrow, in responseto variations in the terrain over which the apparatus 10 travels.

[0018] The second vertical supports 38 are rotatably coupled below thesurface of the feed conveyor 14 about point A, which is acentrally-located universal joint. As the front of the feed conveyormoves upward or downward—either by operation of the herein-describedheight adjustment mechanism or in response to terrain variations—thefeed conveyor is permitted to rotate about points A and B. This permitsthe feed conveyor 14 to remain relatively stable during operation.

[0019] The entire feed conveyor 14 preferably maintains a generallyupward angle, as indicated in FIG. 1. The belt 42 of the feed conveyor14 travels in an upward direction, so as to move harvested produce fromthe front of the feed conveyor 14 upward toward the lift conveyor 16.

[0020] Turning now to the lift conveyor 16, as shown in FIGS. 1 and 2,it is preferably oriented in an upward direction, when viewed movingbackward along the apparatus 10 from the feed conveyor 14. The feedconveyor 14 is preferably oriented at about a 45 degree angle. The belt44 of the feed conveyor 14 preferably has a plurality of outwardlyprojecting steps 46. The purpose of the steps 46 is to prevent theproduce from falling backward as it is moved upward along the liftconveyor 16.

[0021] The lift conveyor 16 is preferably slidably retained on a frame11 on the main body of the apparatus 10, and may be raised or loweredalong the frame 11 by activation of a hydraulic cylinder (not shown).Raising or lowering of the lift conveyor 16 along the frame 11 will alsocause the feed conveyor 14 to be raised or lowered as well, by virtue ofthe herein-described coupling of the feed conveyor 14 to the liftconveyor 16. In this manner, it is possible to raise or lower theexposed cutting blade 15, so as to position it at the desired height foroptimum cutting.

[0022] For purposes of describing the levelling feature of the apparatus10, attention is now drawn to hydraulic cylinders 13 (only one of whichis shown), which couple between axle 35 and the substantially L-shapedmember 37. When it is desired to adjust the horizontal level of theexposed cutting blade 15, typically because of the terrain of the areato be harvested, such levelling can be accomplished by the individualextension or contraction of the hydraulic cylinders 13, which will havethe effect of rotating the substantially L-shaped members 37 about pointB and thereby raising or lowering the side of the feed conveyor 14proximate the activated hydraulic cylinder 13.

[0023] When the produce reaches the topmost point of the lift conveyor16, it will pass to the washing conveyor 18. As the produce moves alongthe washing conveyor 18, it will pass through a washing station 20.Referring now to FIG. 1, the washing station 20 in one embodimentconsists of a plurality of spray nozzles 21 located above the washingconveyor 18, so as to spray water downward onto the produce passingbelow. Referring now to FIG. 3, the washing station 20 in anotherembodiment consists of a plurality of spray nozzles 21 located above thewashing conveyor 18 and a plurality of spray nozzles 21 located belowthe washing conveyor 18. In this embodiment, the produce is sprayed fromabove and below. (In the embodiment shown in FIG. 3, the belt 48 willneed to be configured so as to permit the passage of water therethrough,such as by forming holes in the belt 48. The water sprayed through thespray nozzles 21 is preferably stored in water tank 50.

[0024] Referring now to FIG. 1, in one embodiment, a portion of thewashing conveyor 18 may be left exposed from the top thereof, so as topermit one or preferably two persons 29 to be positioned there. Fromthat position, the persons 29 may inspect the produce as it passes alongthe washing conveyor 18, for purposes of quality control. Alternatively,or in combination with the inspection step, one or more persons 29 couldremove harvested produce (or a portion of harvested produce—e.g., theheart or the leaves) from the washing conveyor 18 for packaging. (Itshould be noted that it would also be possible to position the exposedportion after the washing station 20.)

[0025] Referring now to FIG. 3, in one embodiment, a plurality of shakerbars 52 are positioned below the belt 48, and oriented so that movementof the shaker bars 52 causes shaking of the belt 48. This shakingmovement will cause some of the water remaining on the produce after itspassage through washing station 20 to be removed. Referring now to FIGS.1 and 3, from the end of the washing conveyor 18, the produce will passto a transfer conveyor 22, which is preferably oriented at a right angleto the washing conveyor 18. The transfer conveyor 22 will move theproduce to the elevator conveyor 24. Like the lift conveyor 16, theelevator conveyor 24 preferably has a plurality of outwardly projectingsteps 46 thereon so as to prevent the produce from falling backward asit travels upward. At the terminus of the elevator conveyor 24, at exitpoint B, the produce is dumped into a receptacle (not shown), which maybe a truck bed or other suitable vessel.

[0026] While the invention has been particularly shown and describedwith reference to preferred embodiments thereof, it will be understoodby those skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention. For example, it may be possible to operate thefeed conveyor 14 with the bandsaw 12 as a stand-alone unit, so as toachieve the advantage of automated cutting of the produce—and thenperforming the washing and loading steps separately. Moreover, the feedconveyor 14 and lift conveyor 16 could be combined into a singleconveyor. Still further, it would be possible to eliminate the transferconveyor 22, and instead to configure the elevator conveyor 24 incombination with the steps 46 so that produce could pass directly fromthe washing conveyor 18 to the elevator conveyor 24 without fallingbackward. Yet further, it would be possible to eliminate both thetransfer conveyor 22 and elevator conveyor 24, with dumping of theproduce taking place at the terminus of the washing conveyor 18.

We claim:
 1. A produce harvester comprising, in combination: a mobileharvesting apparatus travelling on a plurality of wheels and powered byan engine; a bandsaw positioned at a front portion of said mobileharvesting apparatus; wherein said bandsaw has an exposed cutting bladelocated at an appropriate height for harvesting produce; and a conveyoradapted to convey produce after it has been harvested by said cuttingblade.
 2. The produce harvester of claim 1 wherein said appropriateheight is between about 0.25″ and 1.5″ from ground level.
 3. The produceharvester of claim 1 wherein a level of said cutting blade isadjustable.
 4. The produce harvester of claim 1 further comprising ahousing concealing said cutting blade as it travels above saidappropriate height.
 5. The produce harvester of claim 1 wherein saidconveyor comprises a first conveyor pivotably coupled to a secondconveyor, and wherein said second conveyor is located on said mobileharvesting apparatus, so that a position of said first conveyor may bealtered during operation of said apparatus while permitting said secondconveyor to remain relatively stable.
 6. The produce harvester of claim5 wherein said second conveyor is slidably retained on said mobileharvesting apparatus.
 7. The produce harvester of claim 1 furthercomprising: a washing station located on said mobile harvestingapparatus; and a washing conveyor located at an end of said conveyor andadapted to transport harvested produce through said washing station. 8.The produce harvester of claim 7 further comprising shaking meanslocated along said washing conveyor for shaking excess water from saidharvested produce after said harvested produce has passed through saidwashing station.
 9. The produce harvester of claim 1 further comprisingan inspection area located along said conveyor wherein one or morepersons can visually inspect harvested produce as it is transportedalong said conveyor.
 10. The produce harvester of claim 7 furthercomprising an elevator conveyor located at an end of said washingconveyor and adapted to transport said harvested produce to areceptacle.
 11. A method of harvesting produce comprising the steps of:providing a mobile harvesting apparatus travelling on a plurality ofwheels and powered by an engine; providing a bandsaw positioned at afront portion of said mobile harvesting apparatus; wherein said bandsawhas an exposed cutting blade located at an appropriate height forharvesting produce; providing a conveyor adapted to convey produce afterit has been harvested by said cutting blade; cutting said produce withsaid cutting blade; and conveying said produce after it has been cutwith said cutting blade on said conveyor.
 12. The method of claim 11wherein said appropriate height is between about 0.25″ and 1.5″ fromground level.
 13. The method of claim 11 wherein a level of said cuttingblade is adjustable.
 14. The method of claim 11 further comprising thestep of providing a housing concealing said cutting blade as it travelsabove said appropriate height.
 15. The method of claim 11 wherein saidconveyor comprises a first conveyor pivotably coupled to a secondconveyor, and wherein said second conveyor is located on said mobileharvesting apparatus, so that a position of said first conveyor may bealtered during operation of said apparatus while permitting said secondconveyor to remain relatively stable.
 16. The method of claim 15 whereinsaid second conveyor is slidably retained on said mobile harvestingapparatus.
 17. The method of claim 11 further comprising the steps of:providing a washing station located on said mobile harvesting apparatus;providing a washing conveyor located at an end of said conveyor andadapted to transport harvested produce through said washing station; andtransporting said harvested produce on said washing conveyor and throughsaid washing station.
 18. The method of claim 17 further comprising thesteps of: providing shaking means located along said washing conveyorfor shaking excess water from said harvested produce after saidharvested produce has passed through said washing station; and saidshaking means shaking excess water from said harvested produce.
 19. Themethod of claim 11 further comprising the steps of: providing aninspection area located along said conveyor wherein one or more personscan visually inspect harvested produce as it is transported along saidconveyor; and at least one person standing in said inspection area andvisually inspecting said harvested produce as it is transported alongsaid conveyor.
 20. The method of claim 17 further comprising the stepsof: providing an elevator conveyor located at an end of said washingconveyor and adapted to transport said harvested produce to areceptacle; and transporting said harvested produce along said elevatorconveyor to said receptacle.